The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A low resistance or a low saturation voltage may be desired in a power semiconductor device in order to reduce the power loss in a conduction state while flowing a very large current. In addition, a high breakdown voltage characteristics, which is a characteristic that may withstand a reverse-direction high voltage applied to both terminals of the power semiconductor device during an off-state or when the switch is turned off, may be desired.
A concentration and a thickness of an epitaxial layer or a drift region of a raw material to form the power semiconductor device may be determined depending on a rated voltage required by a power system. According to a poisson equation, the epitaxial layer or the drift region of the low concentration and the thick thickness may be desired as much as the high breakdown-voltage of the power semiconductor device is desired. However, it might also increase an on-resistance and reduce a forwarding-direction current density. Accordingly, when designing the power semiconductor device, it may be desirable to overcome the above trade-off as much as possible.
In a case of a MOSFET element that includes an inversion layer channel applied with a silicon carbide (SiC), a stage of a silicon oxide layer and a silicon carbide interface is not good and may affect a flow of electrons/current passing through the channel generated adjacent to the silicon oxide layer. As a result, a mobility of electrons may be very low.